Drive units are used in vehicles (notably in automobiles) to transmit a torque generated by a combustion engine towards the wheels of the vehicle. Such drive units typically comprise a transmission with a plurality of different gears and one or more clutches or a clutch unit comprising one or more clutches for coupling or decoupling the transmission with or from the crankshaft of the combustion engine. In particular, an automatic transmission may comprise a plurality of clutches which are used for shifting between different gears and/or for shifting to the different modes N, R and D. By opening a certain number of the plurality of clutches, the torque flow between an input and an output of the automatic transmission, i.e. between a driving shaft and a driven shaft of the vehicle, may be interrupted.
In order to allow for an increased efficiency, a vehicle may be operated in a so called sailing mode, during which the vehicle cruises with the combustion engine being decoupled from the output shaft and/or wheels, i.e. with at least one clutch or clutch unit being disengaged. In case of semi-automatic or automatic transmissions, the clutch may be disengaged automatically when one or more conditions for entering the sailing mode are met. On the other hand, the clutch may be engaged automatically, when one or more conditions for leaving or exiting the sailing mode are met.
Entering and notably exiting the sailing mode should be performed in a manner which remains substantially unnoticed by a driver of the vehicle. The present document describes methods and systems which enable a vehicle to automatically exit a sailing mode, wherein the methods and systems reduce noticeable impacts on the driving experience of a driver of a vehicle, such as a delay of acceleration after actuation of a throttle pedal when coming from the sailing mode compared to when coming from normal driving without sailing.